Although women fatigue less than men, particularly during submaximal contractions, the mechanism underlying the difference is unclear. Ankle dorsi-flexor fatigue was developed through a maximal voluntary contraction sustained for four minutes in older (74 years; N = 19) and younger (33 years; N = 17) healthy, but untrained, males and females.

Females fatigued relatively less than men. There was no age effect. Peripheral factors accounted for much of the gender difference in relative fatiguability.

Implication. Females fatigue less in maximal isometric contractions than do males.